Sealed door construction for dryers and the like



May 1, 1956 J. R. THYGESON 2,743,488

SEALED DOOR CONSTRUCTION FOR DRYERS AND THE LIKE Filed May 25, 1955 E the outwardly biased edge 31a. Over-center movement beyond the edge 31a is limited by the engagement of the portion 28 against the edge 31h. The present construction thus permits the door to springopen automatically when the pressure within the housing exceeds a predetermined safe minimum value. The minimum pressure causing the door to open is determined by the pressure required to close the door against the bias of the resilient strips 22 and 24. If it is desired to change the pressure which springs the door open, the strips 22 and 24 may be adjusted relative to the structural members 16 and 11 respectively by simply' releasing the snap strips 13 and shifting the resilient strips 22 and 24 outwardly of the structural members.

The clearance between the sill and lintel of the door frame and the door is sealed as illustrated in Fig. 3 by strips identical in structure and function to the strips 22 and 24, which therefore need not be described in detail. The hinged edge of the door is also sealed against the escape of the drying medium from the housing. To this end, an elongated L-shaped strip 31, the leg of which is provided with a longitudinal lip 32, is secured to the structural member 16-of the door as indicated in Fig. 2.

The angle between the lip 32 and the body of the member 31 is such `that the member is biased outwardly into lengagement with the hinge plate 33 of the hinge 21. The

hinge plate 33 is continuousalong the length of the door jamb and will, therefore, provide a continuous sealing surface for the member 31. Since the strip 31 is formed of resilient metal, it effectively seats against the hinge plate 33 in sealing engagement and is substantially proof against damage by the high temperature conditions of the dryer. As` with the strips 22 and 24, the strip 31 is releasably secured to the jamb by means of the removable snap strip., 19 and, therefore, may be easily removed and replaced.

The door is sealedaround its complete periphery so that there is no possibility of the escape of the drying medium from the housing. If desired, a door stop 34 ,may be secured to the jamb confrontingthe free edge of the door to prevent excessive strain on rthe sealing member 31 when the door Ais being closed. If desired however, the stop may be eliminated since the'over-center engagement of the bowed body portion 28 with the protruding sealing surface 31a, and the limiting of the overcenter movement by thek edge 31h of the sealing strip 24 effectively seats the door in its proper closed position.

A modified form of the invention is illustrated in Fig. 7 wherein both the door 36 and the frame 37 are provided with U,shaped sealing strips 38 and 39 respectively, each of which is` identical to the sealing strip 22. In this embodiment of the invention', a door stop 40 properly seats the` door in closed position by limitingthe overcenter movement of the center of the strip'38 inwardly of the dryer housing beyond the center ofthe bowed out portion 41 of the strip 39. It should be noted thatvthe door, when closed, is offset relative to the jamb so that the strip 38 seats behind the protruding surface 41. The

offset bowed portions of the strips 38 and 39 thereby constitutel an over-center closure which resiliently maintains the door closed against pressure within the housing. The strips 38 and 39 are resilient to provide an effective seal therebetween, and when the pressure within the housing exceeds a predetermined minimum value it automatically springs the door open to relieve the pressure withinv the housing. As described above in connection with Figs.

1 to 6, the strips 38 and 39 may be adjusted outwardly ofthe structural members 42 to determine the pressure `which automatically springs the door open.

While particular embodiments of the invention hav been illustrated and described herein, it is not intended to limit the invention to such disclosures, and changes and modifications may be made therein and theretowithinthe scope of the following claims.

I claim:

l. In a door assembly comprising a frame member and a door member hingedv'at one edge to said frame for swinging movement therein, a seal construction between the free edge of the door member and the confronting surface of the frame member comprising a first continuous longitudinal resilient strip secured to one of said members and having a portion thereof biased transversely outward to define at least one continuous protruding longitudinal sealing surface, a second continuous longitudinal resilient strip secured to the other member and having a portion biased outwardly for over-center engagement beyond said continuous protruding sealing surface of said first strip, and means to limitA over-center movement of said strip beyond said protruding sealing surface to thereby maintain said strips in continuous sealing engagement with each other.

2. In a door assembly comprising a frame member and a door member hinged' at one edge to said frame for swinging movement therein, a seal construction between the free edge of the door member and the 'confronting surface of the frame member comprising cooperating continuous longitudinal resilient strips mounted respectively on the free edge of the door and the confronting edge of the frame and confined between the planes of the sides of the respective edges, the first of said strips being secured to one of said members and having a portion there of biased vtransversely outward to define at least one con,- tinuous protruding vlongitudinal sealing surface, the second of said strips being secured to the other member and being convex outwardly for over-centerengagement beyond said continuous protrudingsealing surface of said first strip, and means to limit over-center movement of lsaid strip beyond said protruding sealing surface to thereby maintain said strips in continuous sealing'engagement with each other.

3. In a `door assembly comprising a frame member and a door member hinged at one edge to said frame for swinging movement therein, a seal construction between the free edge of the door member and the confronting surface of the frame member comprising a first continuous longitudinal resilient strip secured to one of said members and having a portion thereof biased transversely outward to define atleast one continuous protruding longitudinal sealing surface, a second continuous longitudinal generally U-shaped resilient strip secured to the other member and having its central portion bowed outwardly for over-center engagement beyond said continuous protruding sealing surface of said first strip, and means to limit the over-center movementV of said strip beyond said protruding sealing surface to thereby maintain said strips in continuous sealing engagement with each other.

4. In a door assembly comprising a frame member and a door member hinged at one edge to said frame for swinging movement therein, a seal construction between vthe free edge of the door member and the confronting surface of the frame member comprising a continuous longitudinal generally W-shaped resilient strip secured to one of said members defining a longitudinal channel having itsside; edges biasedA transversely outward to define laterally lspaced continuous protruding longitudinal sealing surfaces, and a continuous longitudinal generally U- shaped resilient strip secured to the other member and havingv its centrallportion` bowed outwardly for overcenter engagement beyond the firstr of said continuous protruding sealing surfaces of said W-shaped strip, the second of said continuous protruding surfaces of said W- shaped strip constituting means to limit the cover-center movement of said strip beyondsaid first protruding sealing surface tothereby maintain said strip in continuous sealing engagement with each other.

5. In a door assembly comprising a frame member and a door member hinged at one edge to said frame for swinging movement' therein, a seal construction between the free'edge of the door member and the confronting surface of the frame member comprising a irst continuous longitudinal generally U-shaped resilient strip secured to one of said members and being bowed transversely outward to dene a continuous protruding longitudinal sealing surface, a second continuous longitudinal generally U-shaped resilient strip secured to the other member and being bowed outwardly for over-center engagement beyond said continuous protruding sealing surface of said rst strip, and stop means to limit the over-center movement of said strip beyond said protruding sealing surface to thereby maintain said strips in continuous sealing engagement with each other.

t 6. In a housing for dryers and the like, a door assembly comprising a frame, and a door hinged at one edge to said frame for swinging movement therein, the free mart ginal edge portion of the door and the confronting portion of the frame each comprising a longitudinal structural member having ateach of the opposite sides thereof a snap strip including a part biased inwardly against the side of said structural member, a continuous resilient sealing strip having its peripheral edge portions embracing said opposite sides of each said structural member and conined between said inwardly biased parts of the snap strips, each said sealing strip having its central portion biased outwardly toward the other to define at least one continuous protruding longitudinal sealing surface, the protruding sealing surface of one of said sealing strips being operable upon inward swinging movement of said door to move over-center beyond the protruding sealing surface of the other of said sealing strips, and means to limit said over center movement of the strips to thereby maintain said strips in continuous sealing engagement with each other.

References Cited in the file of this patent UNITED STATES PATENTS 848,961 Bricker Apr. 2, 1907 1,754,439 Ruth Apr. 15, 1930 1,841,868 Wuebling Jan. 19, 1932 2,533,847 Sullivan et al Dec. 12, 1950 2,575,793 Bush Nov. 20, 1951 FOREIGN PATENTS 210,295 Great Britain Ian. 31, 192,4

512,986 Great Britain Oct. 2, 1939 735,493 France Aug. 30, 1932 833,651 France July 25, 1938 

